Electric burglar-alar



H. C. ROOME. ELECTRIC BURGLAR ALARM.'

No. 247,411. Patented Sept. 201881.

UNITED STATES PATENT OEEICE.

HENRY C. ROOME, OF JERSEY CITY, NEW JERSEY ELECTRIC BURG LAR-ALARIVISPECIFICATION forming part of Letters Patent No. 247,411, datedSeptember 20, 1881.

Application led November 14, 1579. l

the resistance of the line or circuit wire, are dei fective, in thatalarms are liable to be sounded at the o'ice where watch is kept throughthe electrical action of the natural elements by the momentary contactot' another wire or conductor swaying, for instance, in a storm, or evenby induction through adjacent wires. At the oce such an accident causesthe giving of an alarm just as though there had been a change in theresistance within the house, building, or other structure to be guarded,occasioned by the opening and instantaneous closing of a window or door,and frequently much useless trouble is in this way entailed.

The principal object of my invention is to afford a means whereby alarmsoccasioned by momentary changes in the condition of the circuit,accidentally or in any other way, outside the structure to be guardedmay be distinguished from alarms given at or within the structure, evenwherethe latter are caused by the opening ot' a door or window which isinstantly closed again. To this end I combine with the circuit in thestructure to be guarded a mechanism which, when the line or circuit isshort-circuited at or within the structure,

will hold or maintain it short-circuited, preferably leaving` it,however, free to be released at the office.

Another object of the vinvention is to afford provision forcommunicating with theinmates of a structure to be guarded from theoffice, notwithstanding the use ot' the mechanism em-v ployed to hold ormaintain the circuit short-Y circuited, as aforesaid. u

The invention therefore further consists in the combination, with anelectric circuit and an electro-magnet comprised in mechanism forholding or maintaining the circuit short-circuited, of a battery ofsufficient force to enable the electro-magnet to attract an armature toeiiect and maintain the short-circuiting, an

other battery of greater force for causing the electro-magnet to attractanother armature for eti'ecting the operation of an indicator or bell inthe structure to be guarded, and means for bringing either battery intocommunication with the electric circuit at will to attain the desiredend.

ln the accompanying drawings, Figure 1 is a partly sectional side viewof a mechanism to be arranged in accordance with my invention in astructure to he guarded for holding or maintaining the line or circuitcommunicating with theI same short-circuited when short-circuited at orin the said structure; and Fig. 2 is a plan or top View of saidmechanism and a diagram of the circuit, including in the structure to beguarded a resistance-coil or similar device therein and a window, withwhich the circuit communicates.

Similar letters oi reference designate correspondings parts in bothfigures.

. A designates the line-wire, which enters the structure to be guardedand establishes communication between it and the office where watch iskept. Itis connected to a bindingscrew, a, extending from the base-pieceB of the mechanism, for maintaining the circuit short-circuited whenshort-circuited by the opening ot' a window or door in the structure tobe guarded. From the binding-screwathe wire extends to acircuit-breaker, consisting ot a metallic Hap-spring or elastic strip,C, se- 'cured at or near one 'end to the base-piece, and

provided with a thumb-piece or button, b, whereby it may be manipulated.This circuit breaker is combined with a keeper, D, consisting of au arm,of metal or other conducting material, projecting over thecircuit-breaker,

' so that the latter will, when in its normal po- '.sition, maintain acontact with it. This keeper may be pivotcd to the base-piece B, so thatit can be swung aside, out of contact with the circuit-breaker, whendesirable to retain the circuit broken l'or any length of time withoutholding the circuit-breaker depressed.

From the keeper D a wire, E, extends to electro-magnets F, whence awire, G, extends to a binding-screw, c, on the base-board B. From thisbindingscrew c a wire, H, extends to a resistance-coil, I, whenceanother Wire, J,

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extends to a binding-screw, d, and there connects with a wire, K,leading to the ground L.

Branch wires II J are shown as extending from the wires H and J to awindow, W, in the structure to be guarded, and the sash or sashes ofthis windowis or are to be provided with a device or devices whereby,when either is opened, the ends ofthe branch wires El J will beelectrically connected, whereupon the electric current will be short-circuited through them, leaving or cutting out the resistancecoil I.

M designates a vibratory armature, arranged in proximity to one end ot't-he electro-magnets and pivoted to a supporting-bracket, M', so that itcan be attracted by the magnets into contact with them, or, whenreleased, may swing away from them.

Extending from the armature M, in this instance above the same, is anarm, N, of conducting material-such as metal-which, when the armature isattracted to the electromagnets F, comes in contact with an arm, O, of

conducting material, extending from a post, I),

of conducting material, erected on the basepiece B.

A wire,Q, extends from the armature M to the wire G, and is fastened, ashere shown, in the binding-screw c; and another wire, It, extends fromthe post P to the binding-screw d, connecting there with the ground-wireII.

When the windows and doors ofthe structure to be guarded are closedproperly the electric current will enter on theline-wire A, pass throughthe circuit-breaker C, keeper D, and wire E to the electro-magnets F.From thence itpasses along wire Gr to wire H, thence through theresistance-coil I to the wire J, thence to the wire K, and through thelatter to the ground L. Then any momentary change in the resistance ot'the circuit outside the structure will cause only a momentary alarm tobe given at the office with which the line-wire A communicates.

If, however, one of the doors or windowsfor instance, the window V--beopened, the electric circuit will be short-circuited through the branchwires H J', and the resistance-coil I will be short-circuited out.

The electromagnets must be so constructed, and the armature M and thearmature S, presently to be described, so adjusted in respect to theirdistance from the electro-magnets and the strength of the spring wherebythey are returned to their normal position, that when the current isflowing through the resistancecoil wi th its norm al battery-powerneither armature will be attracted, but that when the resistance-coil isshort-circuited out the armature M alone will be attracted.

Whenever the electric circuit is short-circuited through the branchwires H J and the armature M attracted to the electro-magnets, theelectric eurrentwill be short-circuited again, this time through thewire Gr to the wire Q, from the latter to the arm N, thence to the armO, thence through the post P and wire It to the wireK, and to theground. vIn consequence of the latter short-circuiting theelectro-magnels will hold the armature M to them, even if 7o the openeddoor or window be instantly closed again, because the electric currentwill take the easiest course, and an alarm will continue to be givenuntil the existing short circuit is broken by the operator at the ofceopening the line or otherwise, and the release of the armature Meii'ected, whereupon the circuit may be reinstated through theresistancecoil, and the mechanism in the structure to be guarded will bein condition for further use. I employ in connection with this mechanisma lightningarrester, or arrange the circuit-Wires in the structure to beguarded so that they will serve the purpose ot' a lightning-arrester andcause the lightning to pass to the ground without reaching saidmechanism. A suitable instrumentcapable of giving momentaryorlong-continued alarms at the otlice is there connected with theline-wire A. Such instrument may be adapted to give visual or audiblealarms, or both. It may consist of a galvanometer, and the needle ofsuch galvanometer may be made to close a local circuit, to effect theringing ot' a bell or other audible alarm.

The short alarm given through a momentary change in the resistance ot'the electric circuit from any accidental or other cause outside thestructure to be guarded, and the long-continued alarm given through achange in the resistance occasioned at or in the said structure fromshort-circuiting out the resistancecoil, may be easily distinguishedfrom each other; hence the difiiculty heretofore experienced from thefailure to distinguish at the oflice between alarms from such causes andsources is obvi ated.

Although not essential in connection with the above-describedimprovements, I have shown combined therewith an armature, S, actuatedby the electro-magnetsF and carrying a hammer, T, operating a bell,U,and conveying to inmates of the structure to be guarded somepreconcerted message from the operator, or notifying them that theirattention to the operator is desired. This armature S, as beforeintimated, is so adjusted in respect to its distance and the force ofthe spring, whereby it is returned to its normal position, that anelectric current ot' suiiicient force to cause the electro-magnets to-attract the armature M will produce no effect on the armature S. Itherefore provide a battery of greater force for use when the bell U isto be operated. The ordinary battery communicates with the branch wire Aand the more powerful battery with the branch wire Z, and a switch, Y,connected with the line-wire A, and capable of connecting it with eitherofthe branch wires A and Z, enables either battery to actuate the electromagnets F. This combination ofthe electro-magnets F and the twoarmatures M and S is of advan tage when the more powerful battery IOO isconnected with the circuit, for the said battery can draw up thearmature M, thereby short-circuit out the resistance-coil I, and thendraw up the armature S. In this way the armature S can be operated witha much less powerful battery than if the battery had to work against theimpediment of the resistance-coil.

On the top of the bell U, I have also shown an arm or pointer, V, andextending from the arm N an indicator, X, which, by being in contactwith or close proximity to the pointer V, or by being swung awaytherefrom, will indicate Whether the doors and windows of the structureto be guarded are all closed, by showing whether the electric circuit isnot shortcircuited Within the structure or the contrary. When theelectric circuit has been short-circuited before locking up thestructure to be guarded for the night the circuit-breaker O may beemployed to release the armature M, to reinstate the circuit through thestructure and resistance-coil I, and Where the building is to be leftafter being locked the circuitbreaker may be utilized to signal to theoperator at the office Where the watch is kept to reinstate the circuitthrough the structure by opening the line-wire, after the opening andclosing of the door of said structure, to permit the exit of the inmatesof the structure.

It will have been understood from the foregoing description that themechanism for maintaining the circuit short-circuited when it isshortcircuited in the structure to be guarded by the opening of a windowor door there, and the resistance-coil, are located in the structure tobe guarded.

What l claim as my invention, and desire I to secure by Letters Patent,is

1. The combination, with an electric burglaralarm circuit in a structureto be guarded, of a mechanism located at said structure, and which, whenthe line or circuit is short-circuited at or within the structure, willhold or maintain it short-circuited, even after the cause of the alarmis removed.

2. The combination, with an electric burglaralarm circuit in a structureto be guarded, ot` an electro-magnet and arms located at said structureand brought into contact by an armature of said magnet on a change ofresistance in the circuit within the said structure, and serving therebyto short-circuit the said circuit and hold it short-circuited,substantially as and for the purpose specified.

3. The combination, with an electric burglaralarm circuit in a structureto be guarded, of a resistance-coil, an electro-magnet, and arms locatedat said structure, and the arms brought into Contact by an armature ofthe magnet on a change in the resistance in the circuit Within the saidstructure, and serving to short-circuit said circuit and hold ormaintain it short-circuited, substantially as and for the purposespecified.

4C. The combination, with an electric burglaralarm circuit in astructure to bel guarded, of an electro-magnet, arms located at saidstructure and brought into contact by an armature of the magnet on achange of resistance in the circuit within the said structure, servingthereby to short-circuit the circuit and maintain it short-circuited,and a circuit-breaker, substantially as and for the purpose specified.

5. The combination, with an electric burglar-- alarm circuit in astructure to be guarded, ot' an electro-magnet, arms located at saidstructure and brought into contact by an armature of the magnet on achange of resistance in the circuit within the said structure, servingthereby to short-circuit the circuit and maintain it short-circuited,and a circuit-breaker having a keeper pivoted to its support, so that itmay be swung away from said circuit-breaker, substantially as and forthe purpose specified.

6. The combination, with an electric burglaralarm circuit in a structureto be guarded, of an electro-magnet, arms located at said structure andbrought into contact by an armature of the magnet on a change ofresistance in the circuitwithin the said structure, and serving toshort-circuit the circuit and maintain it short-circuited, and anindicator located at said structure for showing whether or not thecircuit is short-circuited, substantially as and for the purposespecitied.

7. The combination of the line-wire A, circuit breaker and keeper U I),wire E, electromagnets F, wire G, wires H H', resistance-coil I, wires JJ', Window W, wire K, armature M, arms N 0, post P, and wire It,connecting with wire K.

8. The combination, with an electric burglaralarm circuit for astructure to be guarded, of

an electro-magnet comprised in mechanism for short-circuitin g andholdingor maintaining the said circuit short-circuited on a change ofresistance within the structure to be guarded, of a battery sufficientin force to enable the electro-magnet to attract an armature and effectand maintain the short-circuitin g, another battery ot' greater forcefor causing the electromagnet to attract another armature to effect theoperation of a bell or indicator in the structure to be guarded, andmeans for bringing either battery into communication with the electriccircuit at will.

9. The combination, with an electric burglaralarm circuit in a structureto be guarded, of an electro-magnet, arms brought into contact by anarmature of the magnet, and serving to short-circuit the circuit withinthe said structure and maintain it short-circuited, and an electric belloperated by the electro-magnet for sounding an alarm in the saidstructure.

- HENRY O. ROOME.

Witnesses:

EDWIN H. BROWN, CHANDLER HALL.

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